Mechanical pressure vessel feedthroughs may be used to transmit axial and/or rotational motion into or out of a pressure vessel depending on the desired movement. When it is desirable to provide both motions into a single feedthrough, however, the mechanisms currently used are vastly different from one another. For a purely rotational feedthrough, for instance, a thrust bearing would usually be used to react to the forces imposed by the pressure difference across the feedthrough shaft. Depending upon the particular application environment these forces can be very high, thereby creating the need for large bearings. The complexity can result in high costs and the friction in such large bearings can be detrimental to system performance. On the other hand, for a purely axial feedthrough, for instance, a linear actuator is used that is large enough to overcome the resulting force due to the aforementioned pressure difference. Similar to the bearings used for rotational transmission, these actuators can be very large, thereby resulting in high costs and occupying more space than may be available for the device.